Synchronous clock system



Nov. 8, 1938. J. w.I BRYCE 2,135,935

SYNCHRONOUS CLOCK SYSTEM med April 11, 1934 V 2 sheets-sheet 1 i12/:ENTA R- f- ATTQRNEY- NOV. 8, J. W BRYCE SYNCHRONOUS CLOCK SYSTEMy Filed April 11, 1954 2 Sheets-Sheet 2 INVENTOR 'ATTORNEY 2@ l IIHHII HHIIIHIHHIIIIHI *l Patented Nov. 8,1938

UNITED STATES PATENT OFFICE SYNCHRONOUS CLOCK SYSTEM Application April 11, 1934, Serial No. 720,015

7 Claims.

This invention relates to a synchronized clock system and more particularly relates to the provision of an improved method for synchronizing secondary impulse clocks which are controlled by a so-called master clock.

The present invention is directed to actuation and synchronization of the secondary Clocks under the control of a master clock by the agency of electrical energy and has for its object the utilization of impulses by an improved secondary clock mechanism for synchronizing the secondary clocks, which impulses are initiated and controlled by the master clock during successive periods of time.

v Various other objects and advantages of my invention will be obvious from the following particular description of one form of mechanism embodying the invention or from an inspection of the accompanying drawings, and the invention also constitutes certain new and novel features of the construction and combination of parts hereinafter set forth and claimed.

In the drawings:

Fig. l is a wiring diagram by which secondary clocks may be actuated and regulated in the practice of the present invention.

Fig. 2 shows the position of the secondary clock mechanism just before release of the stop pawl.

Fig. 3 shows the position of the secondary clock mechanism when stop pawl is released.

Fig. 4 shows the position of the secondary clock mechanism during resetting of released stop pawl.

Master clock- The master clock in its general details may be of any desired form. For example it may be that shown in my prior Patent No. 1,390,018. Referring to Fig. 1, the master clock includes the usual train adapted to drive the minute arbor I6 which makes one` revolution per hour. The usual escapement mechanism II is provided. Fixed to the minute arbor is a cam I2 with two drop-01T shoulders causing contacts I4 to be closed during the intervals between the successive releases of the two levers carrying said contacts.

Preferably, the arrangement of parts is such that the contacts I4 are normally open and are closed for two short intervals during a regular period of about one hour duration. It will be obvious, however, that by a proper rearrangement of the associated parts of the system these cam contacts could operate in a reverse manner being normally closed and opened during the short intervals in the hourly periods.

Also xed to the minute arbor Ill is a cam I5 which is adapted to control the opening and closing of contacts I6. In the preferred embodiment, contacts I6 are' arranged to close for a short period and then open prior to the sixtieth minute.

In addition, the master clock is provided with 5 the usual minute impulse contacts I1 which are `controlled in the usual way from a minute cam I8 or otherwise as is the custom in clocks of this sort.

For accelerating the advance or forward movement of the secondaries quick acting contacts I9 are provided and preferably operated by attaching one of them to the escapement mechanism i l. 'Ihese contacts will close at every movement of the escapement mechanism. 15

Secondary clock- The secondary clock ineluded in Fig. 1 is of conventional form and it includes a minute arbor shaft 2i) which makes one revolution per hour. This shaft is preferably advanced by means of an impulse magnet 2l which acts through the usual ratchet wheel 22 to advance the minute arbor 29 step by step each time the magnet 2l receives an impulse from the master clock. Carried by the minute arbor 2B on each synchronizing clock is a. cam disk 23 provided with a stud 24. Pivotally mounted at 25 is a locking paw] 28 supported bya suitable plate 21 (Fig. 2) in the secondary clock and adapted to cooperate with stud 24 when in the lower position as shownand held in this position by resilient spring detent 28. Also pivotally mounted to plate 21 is lever 29, acted upon by springs 30 and 3l holding said lever in position, and loosely attached to arm 32 cooperatingv with cam disk 23 under influence of spring 33. Also loosely attached tok `lever 29 is link 34 connected to crank lever 35 pivotally mounted at 25 and engaging pin 36 secured to pawl 26. Adapted to engage pin 36 is another lever 31rotatably mounted at 38 and loosely attached to arm 39 provided with a protruding finger 40 adapted to cooperate with disk 23 by virtue of spring 4I.

At the free'i end of arm 39 is an offset 42 adapted to be engaged by extension 43 of armature 44 wheny arm 3,9 is in the position shown in Figs. 2 and vArmature* 44 pivoted at 45 is provided with an.A extension arm 46 adapted to engage arm`32 v'when the described linkage is in a position" as shown in Fig. 4 and to be described hereinafter. Assuming the linkage to be in position asV indicated in Fig. 2, an impulse thru magnet 41 causes its armature 44 to be attracted and engage the olset 42 of arm 39 to force arm 39 downwardly as shown in Fig. 3. Downward movement of arm 39 causes lever 31 to urge pin 36 on pawl 26 upwardly to the position as indicated in Fig. 3 in which position the pawl 26 is retained by coacting spring detent 28 releasing the stud 24 on cam disk 23. After rotation of the cam disk 23 in a clockwise direction for a short period another impulse thru magnet 41 causes its armature 44 to be attracted to engage the arm 32 displaced by the shoulder on cam disk 23. Arm 39 is not engaged by armature 44 when not located in the recess in cam disk 23 and arm 32 is not engaged by armature 44 unless displaced by the shoulder on the cam disk, the said recess and shoulder being so arranged on the cam disk that only one arm, either arm 39 or arm 32 can be engaged by the attracted armature 44 at one time. Engagement of arm 32 by the said armature rocks the arm 32 and lever 29 to the right as shown in Fig. 4 to cause link 34 to urge crank lever 35 downwardly on pin 36 on pawl 26 to restore pawl 26 to its former lower position and in the path of the stud 24 on the disk 23.

The disk is timed with reference to the minute hand of the secondary clock so that when the minute hand indicates the 59th minute the stud on the disk will be close against the pawl 26. When the pawl is raised the stud will befreed as shown in Fig. 3.

Normal operation-A full explanation of a manner in which the method may be practiced will be described with reference to Fig. l.

The first operation to be described will be the normal impulse operation for actuating the secondary clocks. For clarity, it will be assumed that all of the secondary clocks are in a position immediately after the hour reading. Referring to the wiring diagram illustrated in Fig. l current is supplied from a battery indicated at 50 and the clocks are continuously actuated by minute impulses through magnets 2| described above. It is understood that battery 50 is but a conventional designation for a source of electrical impulses and that other forms of impulses besides direct current impulses are within the scope of this invention.

Current from battery 5I! flows thru switch 5I, line 52, contacts I1, magnet 53, line 54 to the common return ground. This current is intermittent due to the periodic closing of contacts I1 by cam I 6 on the minute arbor of the master clock, and therefore contact 55 will be closed and opened at minute intervals. This will allow an intermittent current to iiow from battery 50, line 56, line 51, contact 55, magnets 2| to common return ground, thus causing magnets 2| acting through the ratchet 22 to advance the minute arbor 20 step by step as each minute impulse is received by magnet 2I. All of the secondary clocks 'of the system will be actuated in this manner.

Synchronization.--Synchronization of the secondary clocks to the so-called master clock is maintained hourly by the master clock sending one impulse at some period during the hour and at the same time an impulse energizing magnet 2| is delivered to the secondary system to energize magnets 41 to position locking pawl 26 into the path of stop 24 on cam disk 23 as described hereinbefore, and a second similar impulse later in the same hour period for example the sixtieth minute impulse to energize the magnets 41 to raise the locking pawl 26 to free said stud 24. If any one oi.' the clocks is fast, the minute arbor 26 of the secondary clock will be stopped by its pawl 26 until it has been retarded an amount suilicient to bring it into synchronism with the master clock. The normal position of each pawl 26 as explained is in the path of its respective stud 24 on cam disk 23.

Should any of the clocks be slow they must be stepped ahead at a rapid rate in order that they be on time on the hour. This is accomplished by causing rapid actuations of magnets 2| just before each hour reading of the hands of the master clock. Cam I5 closes contacts I6 preferably ai'ter the fifty-ninth minute and allows a branch current to ow from battery 50, switch 5I, contacts I6, line 58, contacts |9, magnet 53, and line 54 to ground. Contacts I8 close in comparatively rapid succession, for example, once every two seconds and causes the intermittent current set up to energize magnet 53 at the same rate. This results in closing contacts 55 at the same rate and current from battery 50 through lines 56 and 51 through contacts 55 is conducted to magnets 2| thus producing rapid advance of any slowly timed secondary clocks.

In my preferred embodiment, this period of acceleration of the slow clocks occurs shortly after the nity-ninth minute and lasts for about thirty seconds, thus allowing for a positive correction of fifteen impulses each hour. This period may be lengthened if desired, but it must terminate prior to the closing of contacts I4, to cause the release of stop 24, by cam I2 which is timed to close the contacts on the hour.

As stated before, the locking pawl 26 is raised when contacts I4 are closed and when magnet 41 is energized. Energization of magnet 41 occurs when contacts 55 are closed on the hour impulse. Current then Will flow from battery 50, line 56, line 51, contacts 55, line 56, contacts |4, line 60, magnet 6| to ground, energizing magnet 6I to close its contact,62, allowing current from battery 50 to flow thru line 56, contact 62 to magnet 41 to ground. Just prior to the hourly impulse the minute arbor of the synchronized clocks is in a position as shown in Fig. 2, the stud 24 is engaged by locking pawl 26, the extension 40 of arm 39 is cooperating with the recess in cam disk 23 and arm 32 is cleared of the shoulder on said disk. So that energization of magnet 41 at this period, namely, the hour impulse, attracts its armature 44 to engage and depress arm l! to cause the locking pawl 26 to be raised and maintained in the raised position to free stud 24 as explained hereinbefore. Since contacts I4 and contact 62 are closed on the hour, locking pawls 26 will be removed from the paths of the studs 24 on disks 23 and all of the clocks will continue their movement in synchronism.

At some period after the hour contacts I4 are adapted to be closed again by the second shoulder on cam I2, and at the same time the minute impulse contacts I1 are closed, for example, the eighth minute, so that current again flows from battery 50 through lines 56 and 51, now closed contacts 55 due to energization of magnet 53 by the eighth minute impulse, line 56, contacts I4, line 6U, magnet 6I to ground, energizing magnet 6I closing its contact 62. Current then flows from battery 50 thru line 56, contact 62, to magnet 41 and ground, energizing magnet 41. At the tlme the eighth minute impulse is transmitted the minute arbor of the secondary clocks is in a position so that the shoulder on its attached cam disk 23 dlsplaces the cooperating arm 32 to a position as shown in Fig. 4 so that the attracted armature 44 of the energized magnet 41 engages arm 32 to move it to the right as previously explained and in so doing causes the locking'pawl 26 to be reset from its raised position as shown in Fig. 3 to its normal lower position as shown in Fig. 4 to be in the path of cam disk stud 24.

It will be apparent from the foregoing that the period of coincidence of all the clocks in the system described in this embodiment of my invention occurs after the fifty-ninth minute and may last until a few seconds before the sixtieth minute, allowing for an advance of slow secondary clocks of as much as fteen minutes and a retardation of fast secondary clocks of a maximum amount of a little less than fifty two minutes. It is manifestly obvious that the corrections may be relatively varied according to the timing of the various cams.

It will be understood that if in any case it is required to correct the time of the entire system, as for example, when the master clock is running fast or slow and this correction is to be within the range permitted by the synchronizing period it is only necessary to reset the hands of the master clock to the desired extent. The secondaries will then set themselves Within the next hour. If the amount is in excess of the synchronizing period for which the system is designed,

'for example, when a daylight saving correction is required, a manual control is brought into operation as shown in Fig. l which will now be described. Referring to the diagram a wire 65 is provided terminating in a switch point as shown. To retard the secondary clocks the switch 5i is displaced to the open or ofi position. This switch is maintained open for the desired retarding period.` If it is desired to advance the clock, the switch 5l is thrown to connect with the switch point or Wire 65. The effect of connecting switch 5i with wire 65 is to cause the fast set-up contacts I9 to come into action and rapidly advance the various secondary clocks. The switch 5| will be held closed until the secondary clocks advanceV to the desired extent. For example to advance all of the clocks one hour withl contacts iii closing every two seconds it will take two minutes to bring about the proper advance of the secondaries.

It will be understood that it is not essential to hold switch 5| closed for the exact period inasmuch as the synchronizing system will function to bring the clocks in time with the master clock whether the said secondary clocks are fast or slow with respect to the master clock. It is only necessary that they be brought within the range of the synchronizing period.

The above is equally true with regard to retarding operations it being only necessary to open switch 5I for approximately the desired retarding period. y

In Fig. l, three secondary clocks are illustrated showing their time relation to the master clock. The hands and cam disks 23 are shown as rotating in their normal direction.

As stated previously, at the hour all of the secondary clocks behind time will be urged ahead by the rapid series of accelerating impulses, but since clock X is on time it will not be affected for locking pawl 26 is in the path of cam disk stud 24 and will hold the cam disk in position until the stud is freed. Clock Y is shown to be 15 minutes fast and its cam disk locked in position and held so until the hour, while clock Z which is indicated to be 15 minutes slow will continue to operate until it is picked up by the accelerating impulses occurring shortly after the fifty-ninth minute,

and moved ahead until the disk 23 is stopped by pawl 26. Following immediately after the cessation of the accelerating impulses, all the pawls 26 will be raised, and the secondary clocks will then continue to operate in synchronism with the master clock.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the reset without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is as follows:

1. A synchronized clock system including a master clock and a secondary clock, means in the master clock for sending normal driving impulses periodically to the secondary clock, means in the secondary clock controlled by said impulses to advance it accordingly, a device controlled by the master clock for sending additional periodic impulses to the secondary clock, instrumentalities for restraining advancement of the secondary clock when it reaches a certain chronological position, mechanism in the secondary clock positioned in accordance with the chronological position of the secondary clock, and means cooperating with said mechanism and controlled by the said additional impulses so that the receipt of one of such impulses renders the said restraining instrumentalities either to be subsequently effective to prevent further advancement of the secondary clock or to release said restraining instrumentalities depending on the chronological position of the aforementioned mechanism.

2. A synchronized clock system including a master clock and one or more secondary clocks, means in the master clock for sending periodic driving impulses to advance said secondary clocks, means controlled by the master clock for sending additional current impulses to the secondary clocks, blocking means movable into and out of blocking position for restraining advancement of the secondary clock, means settable in accordance with the chronological position of the secondary clock for controlling said blocking means, and electromagnetic means controlled by said additional impulses for moving said blocking means into or out of blocking position in accordance with the setting of said settable means.

3. A synchronized clock system including a master clock and one or more secondaryA clocks, means in the master clock for sending periodic driving impulses to advance said secondary clocks, means controlled by the master clock for sending additional current impulses to the secondary clocks, blocking means movable into and out of blocking position for restraining advancement of the secondary clock, a member movable with the chronological advancement of said secondary clock, a plurality of settable members cooperating with said blocking means and said movable member and positioned in accordance with the chronological position of said movable member, and electromagnetic means common to said settable members for controlling the same to move the blocking means into or out of blocking position in accordance with the position of said settable members.

4. A synchronized clock system including a master clock and a secondary clock, means in the -master clock for sending normal driving impulses periodically to the secondary clock, means in the secondary clock controlled by said impulses to advance it accordingly, means controlled by the master clock for sending additional periodic impulses to the secondary clock, means for restraining advancement of the secondary clock when it reaches a certain chronological position, settable means in the secondary clock positioned in accordance with the chronological position of the secondary clock, means cooperating with said settable means during certain predetermined chronological positions of the secondary clock so that upon receipt of one of said additional impulses the settable means is controlled to render said restraining means to be subsequently effective to prevent further advancement of the secondary clock beyond a certain chronological position, and said last-named means cooperating with said settable means during another predetermined chronological position of the secondary clock so that upon receipt of a successive additional impulse the settable means is controlled to release the restraining means to permit advancement of said secondary clock.

5. A secondary clock including an electromagnet for advancing said clock, a blocking device for restraining advance of said secondary, a cam member driven by said electromagnet, a plurality of cam followers variably positioned at different chronological positions of said cam member, connecting linkages cooperating with said cam followers and said blocking device, and electromagnetic means common to both cam followers for controlling one or the other to control the operation of said blocking device.

6. A synchronized clock system including a master clock and one or more secondary clocks, means in the master clock for periodically transmitting electric impulses for driving the secondary clocks, magnetically operated means in the secondary clocks for blocking advancement of said secondary clocks, said means being. alternately movable into and out of blocking position on successive magnetic operations in accordance with the chronological position of said clock, and means in said master clock for transmitting periodic uni-directional current impulses to said magnetically operated means wherein successive uni-directional current impulses cause alternate movement into and out of blocking position.

'7. A synchronized clock system including a master clock and one or more secondary clocks, means in the master clock for sending normal driving impulses periodically to the secondary clocks, means in the secondary clocks controlled by said impulses to advance the secondary clocks accordingly, means controlled by the master clock for sending additional uni-directional periodic impulses to the secondary clocks, an electro-magnet in each secondary clock operable by said additional uni-directional impulses, means for restraining advancement oi' the secondary clocks when they reach a certain chronological position, means operable in a certain chronological condition of the secondary clocks including means controlled by said electro-magnet upon operation by one of the said additional uni-directional impulses to render the said restraining means to be eil'ective to subsequently prevent further advancement of the secondary clocks when they reach a certain chronological position, and means including means controlled by said electro-magnet upon operation by the next successive additional uni-directional impulse to render said restraining means ineffective, thereby permitting further advancement of said secondary clocks.

JAMES W. BRYCE. 

